Ok, so I have an X99 i7-5820k system with 48gb ddr4 2666mhz, multiple SSD's and HDD's and 750w Supernova EVGA PSU. I was using an old GTX 580 Sparkle card before and getting about 6 to 8 FPS while previewing uncached compositions in After Effects CC 2015. I have now upgraded to a Titan X (maxwell) and I'm not even getting a full frame a second in previewing. Rendering seemed normal, and I did some benchmarking and stress tests just to make sure I didn't have a bunk card, but everything passed with flying colors and I got a pretty nice score in 3Dmark so the card seems to work just fine.
I have done all the things to get after effects to see the card like the gpusniffer and add the cards name to the ray tracing supported cards host file. It shows in AE and allows me to up the graphics memory to 9181mb, and it shows 12gb usable memory in the cuda thing on the bottom of the preview preferences window.
Also, I have someone offering me 2 quadro k4000 cards as a trade for the titan and the guy says they will perform much better for my needs. Is this true? Specs are so much different.
These cards are not yet properly supported in AE. Wait for the next update.